fix the URL of AnyProxy project on github, and fix the way we define the favicon in docs

Author: codingfishman

docs-src/cn/_layouts/layout.html

@@ -18,7 +18,6 @@
                 {% endif %}
             {% endfor %}
         {% endblock %}
-        {% block head %}{% endblock %}
         <link rel="shortcut icon" href="/assets/favicon.png" type="image/png">
         <link rel="stylesheet" href="/assets/website.css">
         <script src="/assets/main.js" ></script>